<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Document</title>
    <script src="./lib/vue-2.4.0.js"></script>
</head>

<body>
<div id="app">
    <input type="text" v-model="n1">
    <select v-model="opt">
        <option value="+">+</option>
        <option value="-">-</option>
        <option value="*">*</option>
        <option value="/">/</option>
    </select>
    <input type="text" v-model="n2">
    <button type="button" @click="calce">=</button>
    <input type="text" v-model="result">

</div>

<script>
    // 创建 Vue 实例，得到 ViewModel
    var vm = new Vue({
        el: '#app',
        data: {
            n1: 0,
            n2: 0,
            opt: "+",
            result: 0
        },
        methods: {
            calce(){
                switch (this.opt) {
                    case "+":
                        this.result = parseFloat(this.n1) + parseFloat(this.n2);
                        break;
                    case "-":
                        this.result = parseFloat(this.n1) - parseFloat(this.n2);
                        break;
                    case "*":
                        this.result = parseFloat(this.n1) * parseFloat(this.n2);
                        break;
                    case "/":
                        this.result = parseFloat(this.n1) / parseFloat(this.n2);
                        break;
                }
            }
        }
    });
</script>
</body>

</html>
